| Message ID | b1577a24c58a9b0605a4540c8be5c411a07cb04c.1713379239.git.bcodding@redhat.com (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | NFSv4: Fixup smatch warning for ambiguous return | expand |
On Wed, Apr 17, 2024 at 02:49:29PM -0400, Benjamin Coddington wrote: > Dan Carpenter reports smatch warning for nfs4_try_migration() when a memory > allocation failure results in a zero return value. In this case, a > transient allocation failure error will likely be retried the next time the > server responds with NFS4ERR_MOVED. > > We can fixup the smatch warning with a small refactor: attempt all three > allocations before testing and returning on a failure. > > Reported-by: Dan Carpenter <dan.carpenter@linaro.org> > Fixes: c3ed222745d9 ("NFSv4: Fix free of uninitialized nfs4_label on referral lookup.") > Signed-off-by: Benjamin Coddington <bcodding@redhat.com> > --- This preserves the existing behavior and makes the code more readable. Reviewed-by: Dan Carpenter <dan.carpenter@linaro.org> regards, dan carpenter
On Wed, Apr 17, 2024 at 02:49:29PM -0400, Benjamin Coddington wrote: > Dan Carpenter reports smatch warning for nfs4_try_migration() when a memory > allocation failure results in a zero return value. In this case, a > transient allocation failure error will likely be retried the next time the > server responds with NFS4ERR_MOVED. > > We can fixup the smatch warning with a small refactor: attempt all three > allocations before testing and returning on a failure. > > Reported-by: Dan Carpenter <dan.carpenter@linaro.org> > Fixes: c3ed222745d9 ("NFSv4: Fix free of uninitialized nfs4_label on referral lookup.") > Signed-off-by: Benjamin Coddington <bcodding@redhat.com> > --- > Chuck, does this look sane? I don't have a simple way to test this at the > moment. Also, I think the only result of returning -ENOMEM here instead > would be that we skip continuing to try to migrate for other filesystems on > this client, and we'd get a log message and trace output of the failure. Reviewed-by: Chuck Lever <chuck.lever@oracle.com> > fs/nfs/nfs4state.c | 12 +++++------- > 1 file changed, 5 insertions(+), 7 deletions(-) > > diff --git a/fs/nfs/nfs4state.c b/fs/nfs/nfs4state.c > index 662e86ea3a2d..5b452411e8fd 100644 > --- a/fs/nfs/nfs4state.c > +++ b/fs/nfs/nfs4state.c > @@ -2116,6 +2116,7 @@ static int nfs4_try_migration(struct nfs_server *server, const struct cred *cred > { > struct nfs_client *clp = server->nfs_client; > struct nfs4_fs_locations *locations = NULL; > + struct nfs_fattr *fattr; > struct inode *inode; > struct page *page; > int status, result; > @@ -2125,19 +2126,16 @@ static int nfs4_try_migration(struct nfs_server *server, const struct cred *cred > (unsigned long long)server->fsid.minor, > clp->cl_hostname); > > - result = 0; > page = alloc_page(GFP_KERNEL); > locations = kmalloc(sizeof(struct nfs4_fs_locations), GFP_KERNEL); > - if (page == NULL || locations == NULL) { > - dprintk("<-- %s: no memory\n", __func__); > - goto out; > - } > - locations->fattr = nfs_alloc_fattr(); > - if (locations->fattr == NULL) { > + fattr = nfs_alloc_fattr(); > + if (page == NULL || locations == NULL || fattr == NULL) { > dprintk("<-- %s: no memory\n", __func__); > + result = 0; > goto out; > } > > + locations->fattr = fattr; > inode = d_inode(server->super->s_root); > result = nfs4_proc_get_locations(server, NFS_FH(inode), locations, > page, cred); > -- > 2.44.0 >
diff --git a/fs/nfs/nfs4state.c b/fs/nfs/nfs4state.c index 662e86ea3a2d..5b452411e8fd 100644 --- a/fs/nfs/nfs4state.c +++ b/fs/nfs/nfs4state.c @@ -2116,6 +2116,7 @@ static int nfs4_try_migration(struct nfs_server *server, const struct cred *cred { struct nfs_client *clp = server->nfs_client; struct nfs4_fs_locations *locations = NULL; + struct nfs_fattr *fattr; struct inode *inode; struct page *page; int status, result; @@ -2125,19 +2126,16 @@ static int nfs4_try_migration(struct nfs_server *server, const struct cred *cred (unsigned long long)server->fsid.minor, clp->cl_hostname); - result = 0; page = alloc_page(GFP_KERNEL); locations = kmalloc(sizeof(struct nfs4_fs_locations), GFP_KERNEL); - if (page == NULL || locations == NULL) { - dprintk("<-- %s: no memory\n", __func__); - goto out; - } - locations->fattr = nfs_alloc_fattr(); - if (locations->fattr == NULL) { + fattr = nfs_alloc_fattr(); + if (page == NULL || locations == NULL || fattr == NULL) { dprintk("<-- %s: no memory\n", __func__); + result = 0; goto out; } + locations->fattr = fattr; inode = d_inode(server->super->s_root); result = nfs4_proc_get_locations(server, NFS_FH(inode), locations, page, cred);
Dan Carpenter reports smatch warning for nfs4_try_migration() when a memory allocation failure results in a zero return value. In this case, a transient allocation failure error will likely be retried the next time the server responds with NFS4ERR_MOVED. We can fixup the smatch warning with a small refactor: attempt all three allocations before testing and returning on a failure. Reported-by: Dan Carpenter <dan.carpenter@linaro.org> Fixes: c3ed222745d9 ("NFSv4: Fix free of uninitialized nfs4_label on referral lookup.") Signed-off-by: Benjamin Coddington <bcodding@redhat.com> --- Chuck, does this look sane? I don't have a simple way to test this at the moment. Also, I think the only result of returning -ENOMEM here instead would be that we skip continuing to try to migrate for other filesystems on this client, and we'd get a log message and trace output of the failure. fs/nfs/nfs4state.c | 12 +++++------- 1 file changed, 5 insertions(+), 7 deletions(-)